Developments in digital printing technology have been progressing at an extraordinary pace in recent years. Digital printing technology is typified by so-called “electrophotographic technology” and “ink jet technology”, and digital printing technology in the form of image formation technology has constituted a growing presence in the office and home in recent times.
Recent years have seen rapid developments in colorization and speed-enhancement in the area of electrophotographic technology, stemming from user-driven demand for faster and more beautiful printing. Accompanying these developments, enhanced technical advantages are being sought from toners that serve as the recording material, and in latter years most kinds of color toners have been changed to polymerized toners in an effort to provide more accurate control. As a polymerized toner for providing enhanced technical advantages, Japanese Patent Application Laid-Open No. 2000-089507 discloses a toner in which three kinds of specific external additives are attached to the surface of the toner. However, a good deal of room still remains for enhancing the performance of toners, and further improvement is required.